I need to know from you good people if Windows XP has been poison-pilled to go bad purposely, to force folks into Windows 7 or 8? Or if this is an issue with my desktop.

I have a Gateway e4100 tower. I bought one off e-bay last October. Ran fine until something odd occurred around April 2nd. My desktop display, my browser windows, everything began to display on a slant. Like if you take a hair comb? And place it on a dresser the the wide-straight-across way? Instead of the narrow-straight-up way? And then you were to slowly push the left side of that comb with your finger, until the comb has gone from wide-straight across, to tilted or diagonal? That's how everything appears in my windows Xp display right now.

This is the weirdest OS issue I've had to deal with in a decade. I've bought 3 replacement e4100 units and they all have the same issue! I thought it could be my hard drive so I switched out drives, and the issue persists. I switched out my crt monitor for a flat screen, issue is still there. I thought it could be a video card issue, but could the video cards be bad in 3 different PC towers? That would be some really bad luck no? Especially considering I've bought all 3 from different e-bay sellers. And the one I got today, is on a PCI card instead of the intel on board graphics chipset. So can anyone properly diagnose this problem for me? What is going on here?